Hydraulic sonic oscillator

ABSTRACT

There is disclosed a linear hydraulic oscillator in which the control valve is positioned in the center of a double-acting piston directly adjacent the pressure chambers to provide a short circuit flow of pressurized fluid directly to and from the pressure chambers.

United States Patent [151 3,678,803

Schwenzfeier [451 July 25, 1972 [54] HYDRAULIC SONIC OSCILLATOR 2,970,570 2/1961 Hill ..91/39 2,220,339 11/1940 Leathem...

[72] Inventor. Otto K. Schwenzfeier, Chula Vista, Calif. 2,4722% 6,1949 Thomas [73] Assignee: Shell Oil Company, New York, NY. 2,876,742 3/1959 Sherrill ..91/39 22 F] d: A .25 1969 1 1e ug Primary Examiner-Martin P. Schwadron pp 352,339 Assistant Examiner-Clemens Schimlkowski AuorneyFreling E. Baker and J. H, McCarthy [521 U.S. Cl. ..9l/39,91/378, 91/466 [51] lm. Cl. ....F15b2/02,F15b 11/08 ABSTRACT Field oiSearch 467, There is disclosed a linear y n oscillator in which the control valve is positioned in the center of a double-acting [56] References C'ted piston directly adjacent the pressure chambers to provide a UNTED STATES PATENTS short circuit flow of pressurized fluid directly to and from the pressure chambers. 3,368,457 2/1968 Lewakowski ..91/39 3,21 1,424 10/ 1 965 Lewakowski ..91/39 6 Claim, 5 Drawing Figures PATENTEBmzs m2 sum 1 or 3 FIG. I M 50 INVENTOR;

OTTO KURT SCHWENZFEIER HIS A ORNEY PAIENTEBJMZ I912 3,678,803 sum a nr 3 FIG. 5

INVENTOR: OTTO KURT SCHWENZFEIER HIS ATTORNEY 1 HYDRAULIC SONIC OSCILLATOR BACKGROUND OF THE INVENTION The present invention relates generally to vibration generators and pertains more particularly to a novel hydraulic sonic generator for converting hydraulic pressure into substantially sinusoidal oscillations.

A great deal of attention has been recently directed toward the use of vibrations both as a testing means and as a workperforming means. One drawback to the extensive use of vibrations in these capacities is the lack of suitable vibration generators often referred to as sonic oscillators or a sonic generator. A number of different types of vibration generators are available, such as the electro-magnetic type and the orbiting mass type. A major drawback of the orbiting mass oscillator, however, is that the frequency and force output are generally dependent on one another. This makes it generally impossible to modify one without modifying the other. The electromagnetic vibrators, on the other hand, are relatively expensive and generally incapable of very high force output.

The prior art hydraulic vibrators have also been unsuitable because of the problems associated with the mass flow of fluid and secondary vibrations resulting therefrom. These problems generally result from the energy expended in reversing the flow of large masses of fluid. This necessary reversal of fluid flow, especially in long channels, oftentimes generate vibrations similar to a water hammer effect, and also may set up standing wave vibrations in the column of fluid itself. Such vibrations from the fluid interfere with the smooth operation of the oscillator as well as introduce secondary vibrations in the apparatus.

Another problem associated with hydraulic vibrators is maintaining a centered stroke and/or full design stroke of the piston. These conditions may result from an external load on the system or from a low operating pressure.

SUMMARY OF THE INVENTION Accordingly, it is the primary object of the present invention to provide a hydraulic sonic vibration generator that overcomes the above disadvantages of the prior art devices.

A further object of the present invention is a provision of a hydraulic vibrator that is capable of putting out very high frequency vibrations.

A still further object of the present invention is to provide a compact hydraulic vibration generator having a very high force output.

In accordance with the present invention a hydraulic oscillator is provided with valving means within the piston and closely adjacent the pressure chamber to reduce the distance that fluid must flow for each stroke thereof, and wherein the valving means are cooperative to automatically control the centering of the oscillator stroke with respect to the oscillator body.

Other objects and advantages of the present invention will become apparent from the following detailed description thereof when read in conjunction with accompanying drawings in which;

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, in section, of a preferred embodiment of the present invention;

FIG. 2 is a section view along line 2-2 of FIG. 1;

FIG. 3 is a view of the embodiment of FIG. 1;

FIG. 4 is a section view along line 4-4 of FIG. 4-4 of FIG. FIG. 5 is aside view, in section, of an alternate embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings and more particularly to FIG. 1 to 4 there is illustrated a preferred embodiment of the present invention comprising a housing and reaction mass member generally designated by the numeral 11, having a cylindrical bore 12 formed therein and a cylindrical cavity 13 concentric with and intermediate the ends of the above-mentioned bore. A piston member 14 is reciprocally mounted in cavity 13 and is carried on a cylindrical body member 15 slidably fitting within cylindrical bore 12. Cylindrical member 15 is formed with a cylindrical throughbore 16 extending su bstantially axially thereof in which is positioned a valve member 17. The valve member 17 is formed with a drive shaft portion 18 extending axially thereof and suitably journaled such as by means of ball bearings 19 in body member 11. A suitable retainer ring 20, retains the inner race 21 of bearing means 19 in position on shaft 18 against annular shoulder 22. The bearing means 19 is preferably mounted such as by being supported by the outer race thereof by means of a pair of resilient rings 24 and 25 which may be of any suitable material such as neoprene.

Suitable means for introducing hydraulic fluid into the system comprises conduit means 26 communicating with annular channel 27 formed in member 11. A plurality of radial ports 28 maintain continuous communication between annular channel 27 in body member 11 and flow channel 29 extending axially along valve member 17. A plurality of radial ports 30 formed in valve body member 17 provide communication between flow channel or conduit means 29 and upper port means 31 in body member 15 which opens into an upper pressure chamber 32 formed by the: upper surface of piston means 14 and the walls of cavity means 13. A second series of circumferentially-spaced ports 33 formed in the lower portion of body member 17 communicates between channel means 29 formed in valve body member 17 and port means 34 formed in member 15 which communicates with pressure chamber 35 formed between the lower surface of piston means 14 and the walls of cylindrical cavity 13. Port means 34 are offset one half pitch from port means 31. Means for exhausting fluid from the pressure chamber comprises channels 36 formed on the outer portion of valve body 17 and adapted to alternately communicate with port 31 and 34 as the valve body member 17 is rotating. This channel 36 further communicates with throughbore 16 which opens into suitable conduit means 37 formed in base member 38. Base plate 38 is coupled in any suitably known manner to load means or apparatus to be driven 39.

Ports 30 and 33 in rotary valve member 17 cooperate with ports 31 and 34 in member 15 to center the system during operation. That is, the piston 14 maintains a centered stroke within cylinder 35 during operation because of this unique valving arrangement. The valve member 17 moves both axi ally and circumferentially with respect to the body member 15. The positioning of the valve ports in combination with the above movement of the valve member results in a valving action that causes a centered operation of the system under normal operating circumstances. This self-centering feature is automatic and can be understood by a study of the port positions as seen in FIGS. 1 and 4. Looking first to FIG. 1, the piston 14 is in its uppermost position in cylinder 13. Under normal operating conditions, the piston 14 will reciprocate within cylinder 13, with inertial mass member 11 remaining substantially stationary while the load member 39 reciprocates at a given amplitude and frequency. In the illustrated position, (FIG. 1) the piston 14 is in its uppermost position within the cylinder 13 and valve member 17 is in its lowermost axial position with respect to piston 14 and is in the proper angular position for communication with port 31. Thus, fluid may flow through ports 30 and 31 into chamber 32 and force the piston downward toward the other end of the cylinder 35. Ports 33 however, are too far down with respect to ports 34 to communicate therewith even if they were in the proper angular position. In other words the lower ports 34 (FIG. 1) are completely cut off regardless of the angular position of the rotor valve 17 when the piston 14 is in its uppermost position, whereas the upper ports 31 are not cutoff. Similarly, the upper ports 31 are cutoff when the piston .17 is in its lowermost position regardless of the angular position of the valve member 17. The ports are constructed and arranged for maximum communication and fluid flow at near center positions and for minimum communication and fluid flow at the extreme positions. Thus, looking at FIG. 4, it is seen that with the piston 14 centered in cylinder 13 port 31 would be in full communication with port 30 if valve 17 were in the proper angular position where the upper edge of port 31 and the upper edge of port 30 are even to a point where the lower edges of the ports are even. The port 31 becomes completely masked out when its upper edge drops to a position below the lower edge of port 30. However, as port 31 becomes completely masked, port 34 is still completely open for full communication. Ports 30 are illustrated as being larger than ports 31. This is a preferred construction, although other relative sizes are possible for satisfactory operation. This relative size affects the range of full communication between the ports. Thus it can be seen that the flow of fluid to each pressure chamber 32 and 35 is controlled by both the axial as well as the angular position of valve member 17 with respect to the ports 31 and 34. This combined valve control automatically adjusts the pressure in the chambers 32 and 35 to maintain the stroke of the piston 14 in a centered position within cylinder 13 with respect to the length of the said cylinder 13. Thus the pressure in either chamber increases as the center of the stroke moves to that side of the center of the cylinder 13 and the pressure in the other chamber decreases. The piston will then move more readily from the high pressure toward the low pressure side of the cylinder and this automatically centers the piston therein. Static centering means to center piston means 14 in cylindrical cavity 13 when the apparatus is not in operation comprises a rod member 14 operatively coupled to base member 38 and extending upward therefrom and through cylindrical bore 41 in housing member 11. Lower spring means 42 abuts against base member 38 and annular shoulder means 43 formed in bore 41. An upper spring means 44 abuts against spring means 43 and suitable means such as a nut 45 on the upper end of rod means 40.

The operation of the apparatus illustrated in FIG. 1 is carried out by supplying a suitable flow of pressurized fluid to channel 26 while rotating member 17 in a manner to obtain a suitable frequency. The frequency of this system per revolu tion of valve body member 17 is determined by the number of port means 30 and 33 distributed around the body member for communications with port means 31 and 34. The port means 30 and 33 and channel means 36 must be alternately positioned such that as a port means 30 and 33 is in communication with channel means 31 or 34. The channel means 36 is in communication with the other of the port means 31 or 34. A plurality of the channel and port combinations are spaced about body member 17 such that a number of oscillations of body member 11 are obtained for each revolution of body member 17. The valve members 17 being rotatably journaled in member 11, moves therewith axially of the piston member 14. Thus, the valving action results from an axial movement of the valve member 17 as well as rotation thereof.

Referring now to FIG. 5, there is illustrated an alternate embodiment of the present invention which comprises a body and inertia member 46 having a throughbore 47 and an annular cavity or cylinder means 48 formed intermediate the ends of the throughbore 47. Piston means 49 formed on cylindrical body member 50 is reciprocally mounted in the annular cavity or cylinder means 48. A cylindrical throughbore 51 is formed in cylindrical body member 50 in which is positioned suitable fluid flow control means which comprises a generally annular manifold member 52 mounted by means of a plurality of resilient members 76 and bolts 77 to housing member 46. A reciprocating valve member 53 is positioned within the central bore 54 of manifold member 52. Suitable prime mover means 55 is operatively coupled by means of a member 56 to the valve member 53 to control the movement thereof. The prime mover 55 comprises a double-acting, reciprocating, solenoid means comprising a pair of annular coil means 57 and 58 fixedly positioned in cylindrical housing portion 52a of member 52. Suitable core means 59 is operatively coupled to tubular member 56 and positioned between annular coil members 57 and 58 and adapted to reciprocate alternately therebetween under the influence of electrical current through the core means. Means for introducing hydraulic fluid into this system comprises conduit means 60 operatively coupled with the member 56. Tubular member 56 communicates with passageway 61 formed in valve member 53 and thereby communicates with a pair of annular channels 62 and 63 formed on the outer surface of valve member 53. These annular channels 62 and 63 selectively communicate with annular channels 64 and 65 formed on the internal surface of manifold member 52 which channels in turn communicate with annular channels 66 and 67 formed on the outer surfaces of manifold member 52. These channels in turn communicate with a plurality of radial ports formed in cylindrical body member 50 and leading to either side of piston member 49 and into pressure chambers 70 and 71 formed by the coaction of piston member 49 andv annular cavity 48. Fluid from pressure chambers 70 and 71 is discharged by means of annular channel 72 on body member 53 coming into communication with either channel 64 and 65 therefrom which communicates with conduit means 74 in base or work member 75.

I claim as my invention:

1. A hydraulic oscillator, said oscillator comprising:

an inertia body member;

a cylindrical bore formed in said body member;

a sleeve-like piston member having a single flange-like piston surrounding a central part thereof, the piston member being reciprocally mounted within the cylindrical bore in said body member, the bore defining opposing pressure chambers on opposite faces of the flange-like piston, the piston member being coupled to a load to be oscillated, the piston member being much less massive than the body member; central throughbore extending axially of said piston member;

a movable valve member mounted in said throughbore for movement axially therein relative to said piston member, the piston member and said pressure chambers being radially outward of the valve member and closely adjacent thereto; and

a plurality of basically radially-directed channels formed in said valve member and co-operable with radially-directed channels in said piston member to alternately direct fluid to said opposing pressure chambers on opposite sides of said piston to cause reciprocation thereof with respect to said body member, the channels in the piston member being of length less than the largest cross-sectional dimension of said pressure chambers.

2. The apparatus of claim 1 comprising:

bearing means rotatably supporting said valve member in said body member.

3. The apparatus of claim 1 comprising:

motor means mounted in said body member and operative to move said valve member axially of said piston member.

4. The apparatus of claim 1 wherein the piston means includes sleeve means extending axially in the cylindrical bore and having a length greater than the axial length occupied by said pressure chambers.

5. The apparatus of claim 4 wherein the opposite faces of the piston members are defined by a flange-like projection on said sleeve means.

6. A hydraulic oscillator, said oscillator comprising:

an inertia body member;

a first cylindrical bore formed in said inertia body member;

a sleeve-like piston member having a single flange-like piston surrounding a central part thereof, the piston being reciprocally mounted within the first cylindrical bore in said body member and adapted to be coupled to a work member, the first cylindrical bore defining opposing pressure chambers on opposite transverse faces of the flangelike piston, the piston member being coupled to a load to be oscillated, the piston member being much less'massive than the body member;

a second cylindrical bore formed in and extending axially of said piston member, the pressure chambers and said opposite transverse faces of the piston member being located at positions radially spaced outwardly from the second cylindrical bore and closely adjacent thereto;

a movable valve member rotatably journaled in said inertia member and extending into said cylindrical bore in said piston member for both rotary and axial movement relative to the piston member;

a fluid supply channel extending axially of said valve member;

a plurality of first ports communicating with said supply channel and directed radially from said valve member; and

a plurality of radially-extending second ports formed in said piston member and cooperable "with said plurality of first ports to direct fluid to alternate sides of said flange-like piston to cause reciprocation thereof during rotation of said valve member, said port means being cooperable in response to the axial position of said valve member in said piston member to alter the flow of fluid to alternate sides of said piston member to maintain the stroke of said piston member automatically centered within said first cylindrical bore, the second ports being of length less than the largest cross-sectional dimension of the pressure chambers. 

1. A hydraulic oscillator, said oscillator comprising: an inertia body member; a cylindrical bore formed in said body member; a sleeve-like piston member having a single flange-like piston surrounding a central part thereof, the piston member being reciprocally mounted within the cylindrical bore in said body member, the bore defining opposing pressure chambers on opposite faces of the flange-like piston, the piston member being coupled to a load to be oscillated, the piston member being much less massive than the body member; a central throughbore extending axially of said piston member; a movable valve member mounted in said throughbore for movement axially therein relative to said piston member, the piston member and said pressure chambers being radially outward of the valve member and closely adjacent thereto; and a plurality of basically radially-directed channels formed in said valve member and co-operable with radially-directed channels in said piston member to alternately direct fluid to said opposing pressure chambers on opposite sides of said piston to cause reciprocation thereof with respect to said body member, the channels in the piston member being of length less than the largest cross-sectional dimension of said pressure chambers.
 2. The apparatus of claim 1 comprising: bearing means rotatably supporting said valve member in said body member.
 3. The apparatus of claim 1 comprising: motor means mounted in said body member and operative to move said valve member axially of sAid piston member.
 4. The apparatus of claim 1 wherein the piston means includes sleeve means extending axially in the cylindrical bore and having a length greater than the axial length occupied by said pressure chambers.
 5. The apparatus of claim 4 wherein the opposite faces of the piston members are defined by a flange-like projection on said sleeve means.
 6. A hydraulic oscillator, said oscillator comprising: an inertia body member; a first cylindrical bore formed in said inertia body member; a sleeve-like piston member having a single flange-like piston surrounding a central part thereof, the piston being reciprocally mounted within the first cylindrical bore in said body member and adapted to be coupled to a work member, the first cylindrical bore defining opposing pressure chambers on opposite transverse faces of the flange-like piston, the piston member being coupled to a load to be oscillated, the piston member being much less massive than the body member; a second cylindrical bore formed in and extending axially of said piston member, the pressure chambers and said opposite transverse faces of the piston member being located at positions radially spaced outwardly from the second cylindrical bore and closely adjacent thereto; a movable valve member rotatably journaled in said inertia member and extending into said cylindrical bore in said piston member for both rotary and axial movement relative to the piston member; a fluid supply channel extending axially of said valve member; a plurality of first ports communicating with said supply channel and directed radially from said valve member; and a plurality of radially-extending second ports formed in said piston member and cooperable with said plurality of first ports to direct fluid to alternate sides of said flange-like piston to cause reciprocation thereof during rotation of said valve member, said port means being cooperable in response to the axial position of said valve member in said piston member to alter the flow of fluid to alternate sides of said piston member to maintain the stroke of said piston member automatically centered within said first cylindrical bore, the second ports being of length less than the largest cross-sectional dimension of the pressure chambers. 